An Australian retailer listed various AMD B550 motherboards from Asus at cheap prices.
AMD B550 Motherboards Should Still Be Easy on Wallets : Read more
AMD B550 Motherboards Should Still Be Easy on Wallets : Read more
From what I remember reading, there were concerns over real-world signal integrity in many boards that OEMs enabled 4.0 on. So AMD put the brakes on it, rather than risk having problems dumped in their lap. Of course no third parties tested speeds and error rates as compared to an X570 so who knows how widespread the issues were (or were not).Many 300-series and even more 400-series boards could handle PCIe 4.0 from the CPU perfectly fine until AMD decided to push microcode to disable it. There is effectively no reason for B550 boards to be any more expensive than B450 models other than the chipset cost and any additional improvements motherboard manufacturers may add on top. I'd like to see some real 6+2 phases VRM options.
You already got that: the lowest-end X-series motherboards have the same fat (double-FET) 4+2 phases commonly found on A/B-series motherboards, real 6+2 would be an improvement for those too. Some boards already have doubled-up drivers and chokes too. In those cases, the only real added cost is ~$1 for the controller upgrade a good chunk of which canceled out from removing 1/4 of the doubled quad.As far as VRM options go, I'd like to see them go even higher and undercut the entry-level X570 boards by $10-20, while matching in power delivery.
You're saying a native 6+2 would deliver more power than an equivalent doubled 4 + 2?You already got that: the lowest-end X-series motherboards have the same fat (double-FET) 4+2 phases commonly found on A/B-series motherboards, real 6+2 would be an improvement for those too. Some boards already have doubled-up drivers and chokes too. In those cases, the only real added cost is ~$1 for the controller upgrade a good chunk of which canceled out from removing 1/4 of the doubled quad.
One major problem with doubling FETs is that they will practically never be perfectly matched in on-resistance, temperature, switching speed, etc. and all of these increase losses. If each switching pair has its own inductor, cross-conduction losses can be reduced but the current mismatch between the two phase halves will increase and at this point, you practically have all the components necessary for 8+2 apart from the VRM controller.You're saying a native 6+2 would deliver more power than an equivalent doubled 4 + 2?
The PCB quality of B450 board was not high enough to meet the SNR Requirements of the PCIe 4.0 - Increase the PCB quality is a cost so that's reason one. Also B450 Boards have been on the market for a long time, so the cost of production was calculated in a Pre-COVID19 world and have simply been in inventory for the most part. Supply chain cost has increased and thus resulting product cost will increase. Also there is an initial release price and a price after 3 years of shelf lifeMany 300-series and even more 400-series boards could handle PCIe 4.0 from the CPU perfectly fine until AMD decided to push microcode to disable it. There is effectively no reason for B550 boards to be any more expensive than B450 models other than the chipset cost and any additional improvements motherboard manufacturers may add on top. I'd like to see some real 6+2 phases VRM options.